Web scouring method and apparatus

ABSTRACT

A method and associated apparatus are provided for scouring knit fabrics such as tricots the edge of which tend to curl. The web of material is fed onto a pair of running pin chains which engage the marginal edges of the material and carry it in a flat condition through a scouring station. Scouring liquid is delivered over the web by pressure sprays as well as sheets of liquid to remove oils and dirt. The pin chains then carry the web over a vacuum slot which removes most of the liquid from the center portion of the web. High pressure air jets are located along the path of travel of the web and positioned to direct high pressure air jets against the web edges to remove moisture therefrom. The web is then carried through a drying chamber using heated air and vapor mixture. Chemicals of various types can be applied with a high degree of penetration by the use of one or more suction boxes located at or after a chemical application station.

United States Patent [191 Holm [ Nov. 13, 1973 WEB SCOURING METHOD AND APPARATUS [75] Inventor: William J. Holm, Springfield, Vt.

[73] Assignee: Riggs & Lombard, lnc., Lowell,

Mass.

[22] Filed: Apr. 17, 1972 [21] Appl. No.: 244,584

[52] U.S. Cl 8/149.1, 8/151, 68/20, 68/205 R [51] Int. Cl B05c 9/12, B05c 9/14, B050 11/12 [58] Field of Search 8/151, 149.1, 149.2; 68/20, 205 R [56] References Cited UNITED STATES PATENTS 1,723,514 8/1929 Klein 8/151 2,613,521 10/1952' Walmsley 8/151 2,613,522 10/1952 Heffelfinger. 8/151 X 2,646,341 7/1953 Fetscher 8/151 X 2,669,502 2/1954 Walmsley 8/151 X 2,785,042 3/1957 Grajeck et al. 8/151 Primary Examiner-William 1. Price Attorney-Gerald Altman et al.

[57] ABSTRACT scouring station. Scouring liquid is delivered over the web by pressure sprays as well as sheets of liquid to remove oils and dirt. The pin chains then carry the web over a vacuum slot which removes most of the liquid from the center portion of the web. High pressure air jets are located along the path of travel of the web and positioned to direct high pressure air jets against the web edges to remove moisture therefrom.

The web is then carried through a drying chamber using heated air and vapor mixture. Chemicals of various types can be applied with a high degree of penetration by the use of one or more suction boxes located at or after a chemical application station.

12 Claims, 5 Drawing Figures 1 WEB SCOURING METHOD AND APPARATUS BACKGROUND OF THE INVENTION to the threads and filaments as a lubricant, particularly.

during the early stages of fabric production. These oils as well as other impurities, once they have served their purpose, must be removed at a later stage to provide a clean and finished product.

In my co-pending application Ser. No. 207,430, filed Dec. 13, 1971 under the title Method & Apparatus For Treating Fabric" and assigned to the same assignee as the present application, there is disclosed a method and apparatus particularly useful for solvent scouring flat tubular or open width webs and subsequently drying the web without stretching or otherwise damaging the web. It has been found that such equipment works well with most fabrics but not completely efficient in handling those materials the edges of which tend to curl. The edges of knit fabrics, particularly tricots, have a marked tendency to curl and this characteristic inhibits scouring and drying of the web across its whole width. This curling characteristic also impairs the handling of the material. Also, where a liquid such as finishing chemical is applied in place of or after scouring, penetration into the fabric has been rather poor.

Accordingly, it is an object of the present invention to provide improvements in methods and associated apparatus for the solvent scouring of running webs, particularly" knit fabrics such as tricots, the edges of which tend to curl. Another object of the invention is to provide a method and apparatus for. improving the penetration of chemicals into a runningfabricweb.

SUMMARY OF THE- INVENTION This invention features a method and associated apparatus for solvent scouring and otherwise treating a running web of material, particularly those types of material the edges of which tend to'cu'rl, comprising the steps of marginally gripping the edges of the web and carrying it in a flat condition through a scouring station, applying a scouringsolvent or thelike under both pressure and volume conditions onto the web, applying a vacuum across the center'portion of the web to remove excess liquid, directing jets of air to the marginal edges to remove liquid from the curled edges, and finally drying the web. A second liquidsuch as a finishing chemical may be applied to the web after securing and a second vacuum employed across the web to achieve deep penetration of the second liquid into the fabric.

The apparatus includes a pair of pin chains'and a housing enclosing at least a substantial portion of the pin chains whereby a web can be marginally attached to the chains and carried in flat condition through the housing. The housing includes a solvent scouringstation comprised of pressure and volume. spray bars adapted to apply a solvent across the width of the web under both pressure and volume conditions and an associated incremental recycling arrangement for the solvent. The housing also includes one or more suction boxes disposed along the path of travel of'the web between the pin chains for removing the solvent from the center portion of the web, and to produce deep penetration of .finishing chemicals or the like applied after scouring. High pressure air jets are located adjacent to edges of the web to drive out moisture therefrom. The housing finally includes a drying chamber employing heated air and vapor to dry the web.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat schematic sectional view in side elevation of a scouring apparatus made according to the invention, A 7

FIG. 2 is a detailed top plan view showing a section of fabric and'pin chains,

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2,

FIG. 4 is a detailed side elevation showing the chain width adjustment mechanism, and,

FIG. 5 is a front elevation of the FIG. 4 apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the reference character 10 generally indicates an apparatus for solvent scouring or otherwise cleaning or treating a running fiat web 12. The apparatus is particularly useful in the scouring of materials whose edges tend to curl. Knit materials suchas tricots display anedge curling tendency and the apparatus is particularly useful in scouring such material. The apparatus is generally organized about a housing comprised of top and bottom walls 14 and 16, end walls 18 and 20 and side walls22, and 24. The walls form a'closed housing having inlet and outlet slots 26 and 28 at opposite ends through which the web 12 is fed into and out of the apparatus.

The web l2 is first fed onto a "pair of parallel pin chains 30 and 32, each chain comprising a loop of chain links, a flexiblebelt or the like provided with a plurality of spaced'pins 33 extending outwardly to engage the marginal'edges of the'w'elx Various types'of pin chains may be employed for'this'purpose. 'Devices such as tenter frames in which clips attache d to belts or chains grip the edges of thematerial, flexible metal bands with hooked teeth, or other types of edgeengaging devices may be employed. I

In the illustrated embodiment, the pin chains 30 and 32 form closed loops which are carried continuously through. the housing 10 guided by a number of pulleys rotatably mountedboth inside and outside the housing. The pin chains 30 and 32 may be adjusted as to their spacing from one another in order to accommodate webs of different widths. The mechanism to carry out the pin chain adjustment is best shown in FIGS. 4 and 5 wherein. pulleys 34 and 36 support, respectively the ,pin chains 30 .and. 32 and are carried by brackets 38 threaded at opposite ends and rotatably supportedby bearings 48 and 50. A hand crank or the like is provided at one end of the lead screw and it will be understood that by turning the lead screw in one direction or another, the bushings 42 and 44 together with the pulleys 34 and 36 may be moved to or away from one another as required to accommodate a web of a particular width. To keep the bushings 42 and 44 from turning with the lead screw various means may be provided to position the pulleys in the required orientation. In FIG. the bushings 42 and 44 are formed with depending fingers S4 and 56 which travel in a slot formed lengthwise of a fixed guide rod 56 extending parallel to the lead screw 46. In this fashion, the bushings will remain upright as they are moved in and out upon an adjustment of the spacing between the pin chains.

The chains 30 and 32 may be suspended between adjacent pulleys or, as shown, the chains may ride on rails 60 which support the chains and prevent sagging between adjacent pulleys. The rails 60 may be of steel or the like and typically each is formed with a U-shaped upper channel serving to guide the chains as they move lengthwise through the housing. Where the pin chains are adjustable as to width the rails 50 preferably are carried on the same support that carries the pulleys namely, the brackets 38 and 40, so that in any spacing adjustment of the pulleys and chains, the rails will be adjusted at the same time.

In FIG. 1 the web 12 is fed onto the pin chains 30 and 32 at the start of an inclined upper reach exterior of the housing and provided with an applicator roll 62 which is disposed above each pin chain and adapted to press the marginal edges of the web onto the pins 33. The applicator roller may be in the form of a rotary brush or the like causing the fabric to press down onto the pins 33, thereby securely holding the web during its passage through the apparatus. The web is then carried up the inclined reach of the pin chains and then is fed downwardly through the slot opening 26 into the housing and through a scouring station 64 wherein a scouring solvent or other liquid is applied to the web across its full width. The scouring station includes a plurality of spray bars 66 and 68 of alternating configuration. The spray bars 66 are in the form of pipes or other conduits provided with spaced nozzles directed at the web and adapted to apply high pressure jets 70 of the solvent across the width of the web. Thenext adjacent spray bar 68 is also in the form of a pipe extending transversely above the web and likewise is formed with spaced orifices which are oriented in the same direction as the web or perpendicular to the jets 70. An arcuate baffle 72 is attached to the spray bars 68 opposite the orifices and serves to convert the spray discharge into a continuous sheet or curtain 76 of solvent which pours in a heavy volume across the width of the web. Thus, the web is subjected alternately to high pressure jets of solvent and then to high volume low pressure sheets of solvent. This alternating scouring technique insures a highly efficient cleaning action in removing oils and dirt from the web. The alternating spray bars extend not only above the inclined path of the web but also above a horizontal reach as the web and chains level off within the housing.

The solvent that is passed through the web is collected and recirculated in stages as described more fully in the above-described, co-pending application. In general, the recirculation system involves separate collection troughs 80, 82 and 84, each with its own pump 86, 88 and 90 which connect with the spray bars in such a fashion that fresh, clean solvent, first introduced through a spray bar 92 at the end of the scouring station and its drains collected in the trough 84, is recirculatedby the pump 90 to a group of spray bars adjacent the bar 92. Likewise, the drains collected in the trough 82 are recirculated to the next group of spray bars and the final drains in the trough 80 are recirculated in the spray bars disposed along the inclined portion of the scouring station. The overflow from the drain trough 80 is collected and returned to a still.

From the scouring station, the pin chains carry the web over a suction box 94 provided with a slot 96 formed lengthwise along its upper portion. The suction box is connected to a vacuum source and serves to remove most of the scouring liquid from the body of the web. Insofar as the suction box is located between the pin chains, it is ineffective in removing solvent from the edges which are carried by the pin chains. In order to drive out the solvent from the edges of the web high pressure air jets are directed by means of nozzles 98 and 100 positioned above and directed downwardly and outwardly towards the web edges. The air jets will not only flatten out the edges but will also drive out most of the solvent that had been applied in the scouring station and which the vacuum slot could not contact. In practice, the high pressure air jets may be a mixture of air and vapor from a drying chamber 102 at the right-hand end of the housing as viewed in FIG. 1.

From the suction box and air jets, the web is carried under an optional spray station 104 where any one of a variety of chemicals may be applied such as a finishing treatment sold under the trademark SCOTCH- GUARD by 3M Corporation. A second separate suction box 105 is located below the web at or after the station 104 to pull the chemical through the web and assure deep penetration of the chemical into the fabric.

From the station 104 where a mixture of heated air andsolvent vapors is continuously recirculated around and through the web to dry the web before it is carried up and out of the housing through the slot 28. The drying chamber is provided with duct work connected to heaters and with condensers. The pin chains can follow reversing paths to provide multiple passing of the web in the drying chamber to insure complete drying action.

The web may be carried only by the pin chains or, if desired, the centerportion' of the web may be alsosupported during certain portions of its travel. For example, a foraminous plate may be mounted in the scouring station directly opposite the spray bars below the web and the pin chains may carry the web over the foraminous plate so that the liquid will pass through the web as well as through the plate. A number of idler rolls may also be employed in place of a fixed plate to support the center part of the web where needed. Also, the pin chains may be separately driven by variable speed motors to permit one side of the web to move slower or faster than the other side and thus correct for any skewing of the materiali' By using the technique and apparatus in connection with tricots and other materials having the edge-curling characteristic, satisfactory results are achieved both in the scouring as well as the handling of the material since the entire width of the material will be effectively treated without the edge folding over, becoming creased, flattened or the like.

Having thus describedthe invention what I claim and desire to obtain by Letters Patent of the United States is: a

1. The method of treating a running fabric web with liquid chemicals, comprising the steps of a. marginally gripping and moving said web in a flat condition along a longitudinal path,

b. applying a liquid chemical across the width of said web,

c. applying a vacuum across the center portion of said web,

d. applying jets of gas against the marginal edges of said web, and,

e. drying said web.

2. The method of claim 1 wherein said chemical is applied alternately in the form of high pressure jets and continuous sheets extending transversely of said web.

3. The method of claim 2 wherein said chemical is recirculated in discrete quantities.

4. The method of claim 1 including the steps of applying a different chemical across said web after applying and evacuating the first chemical and then applying another vacuum across said web to cause said different chemical to penetrate said web.

5. Apparatus for treating a fabric web, comprising a. a housing,

b. web edge engaging means passing through said housing and adapted to engage the opposite edges of said web and carry it in a flat condition longitudinally through said housing,

c. a treatment station within said housing along the path of said web and adapted to deliver a liquid chemical over said web,

d. a vacuum box mounted within said housing and extending into suction contact with the mid-portion of said web to remove excess chemical therefrom,

e. at least one nozzle mounted adjacent each margin of said web directed at the edges of said web and adapted to deliver gas under pressure against said edges, and

f. heating means in said housing for drying said web.

6. Apparatus according to claim 5 wherein said web edge engaging means are mounted for movement to and away from one another to accommodate webs of different widths.

7. Apparatus according to claim 5 wherein said web edge engaging means includes at least a pair of flexible members, a plurality. of pulley engaging means mounted to said housing and engaging said members and a plurality of web gripping elements spaced along said members.

8. Apparatusaccording to claim 7 wherein said elements are pins.

9. Apparatus according to claim 7 including fixed rails mounted between adjacent pulleys and supporting said members.

10. Apparatus according to claim 7 including adjustment means operatively connected to at least the pulleys along one side of said web for selectively varying the spacing with the pulleys along the opposite side.

11. Apparatus according to claim 5 wherein said treatment station includes at least one conduit extending in spaced transverse relation to said web and formed with a plurality of orifices adapted to direct jets of solvent directly onto said web and at least another conduit extending in spaced transverse relation to said web, said other conduit being formed with spaced orifices directed generally parallel to the path of said web and an arcuate baffle mounted to said other conduit opposite said orifice and adapted to form individual jets of solvent into a continuous sheet poured over said web.

12. Apparatus according to claim 5 including a second treatment station within said housing after said vacuum box for applying a second liquid chemical onto said web and a second vacuum box in suction contact with said web for pulling said second chemical through said web. 

2. The method of claim 1 wherein said chemical is applied alternately in the form of high pressure jets and continuous sheets extending transversely of said web.
 3. The method of claim 2 wherein said chemical is recirculated in discrete quantities.
 4. The method of claim 1 including the steps of applying a different chemical aCross said web after applying and evacuating the first chemical and then applying another vacuum across said web to cause said different chemical to penetrate said web.
 5. Apparatus for treating a fabric web, comprising a. a housing, b. web edge engaging means passing through said housing and adapted to engage the opposite edges of said web and carry it in a flat condition longitudinally through said housing, c. a treatment station within said housing along the path of said web and adapted to deliver a liquid chemical over said web, d. a vacuum box mounted within said housing and extending into suction contact with the mid-portion of said web to remove excess chemical therefrom, e. at least one nozzle mounted adjacent each margin of said web directed at the edges of said web and adapted to deliver gas under pressure against said edges, and f. heating means in said housing for drying said web.
 6. Apparatus according to claim 5 wherein said web edge engaging means are mounted for movement to and away from one another to accommodate webs of different widths.
 7. Apparatus according to claim 5 wherein said web edge engaging means includes at least a pair of flexible members, a plurality of pulley engaging means mounted to said housing and engaging said members and a plurality of web gripping elements spaced along said members.
 8. Apparatus according to claim 7 wherein said elements are pins.
 9. Apparatus according to claim 7 including fixed rails mounted between adjacent pulleys and supporting said members.
 10. Apparatus according to claim 7 including adjustment means operatively connected to at least the pulleys along one side of said web for selectively varying the spacing with the pulleys along the opposite side.
 11. Apparatus according to claim 5 wherein said treatment station includes at least one conduit extending in spaced transverse relation to said web and formed with a plurality of orifices adapted to direct jets of solvent directly onto said web and at least another conduit extending in spaced transverse relation to said web, said other conduit being formed with spaced orifices directed generally parallel to the path of said web and an arcuate baffle mounted to said other conduit opposite said orifice and adapted to form individual jets of solvent into a continuous sheet poured over said web.
 12. Apparatus according to claim 5 including a second treatment station within said housing after said vacuum box for applying a second liquid chemical onto said web and a second vacuum box in suction contact with said web for pulling said second chemical through said web. 